The following information is provided to assist the reader in understanding technologies disclosed below and the environment in which such technologies may typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless clearly stated otherwise in this document. References set forth herein may facilitate understanding of the technologies or the background thereof. The disclosures of all references cited herein are incorporated by reference.
In a number of embodiments hereof, separation devices, systems and methods for separation of materials are based upon differences in densities in, for example, separation of solid particles from liquids.
In a number of situations arising in many settings, it is desirable to separate mixtures of materials of different density. For example, it is often desirable to remove particles from a liquid “contaminated” with such particles. For example, in the machining industry coolant liquid becomes contaminated with metal particles having a density generally greater than the liquid coolant.
Centrifugal force effects have been used to separate heavier fractions from lighter fractions in aqueous slurries. For example, U.S. Pat. No. 6,036,871 discloses a separation device in which a slurry is made to spin in a separation chamber under influence of a differential pressure. The differential pressure is generated using a pressure increasing stage including a transport rotor device operating in conjunction with a stator arrangement. The pressure increasing stage is in placed immediately upstream of an inlet of the slurry into the separation chamber. The separation chamber can include a cyclone rotor device. In one embodiment, the rotor blades of a cyclone rotor device and rotor blades of the transport rotor device are mounted on the same rotary shaft. The separating chamber of U.S. Pat. No. 6,036,871 includes a tubular cylindrical housing translating into a funnel-shaped bottom portion which tapers into a discharge opening at the lower end. The hollow rotary shaft protrudes coaxial to the longitudinal centerline of the separation chamber. The end or opening of the hollow rotary shaft is positioned at a distance suitably spaced away from the plane from which the funnel-shaped portion extends downwards. Heavier fractions are collected at an outlet at the bottom of the funnel shaped portion while lighter liquid fractions pass through an upper outlet in fluid connection with the opening of the hollow shaft.
U.S. Pat. No. 5,330,641 discloses a separator of solid particles for variable flow rates of discharge from a dental apparatus. The separator includes a container including an upper cylindrical zone having an inlet hole for the fluid to be separated. A rotor of a centrifugal pump rotates in the upper cylindrical zone, which initializes a separation of the particles by centrifugation. The separator further includes a truncoconical zone which functions as a cyclone and continues the separation of the solid particles.
Mechanical elevators or augers have also been used to convey solid particles from a liquid as disclosed, for example, in U.S. Pat. Nos. 4,294,695 and 4,364,831.
U.S. Pat. No. 7,520,997 discloses a separation system based upon density differences in which a pressurized fluid is delivered to the system inlet and rotational motion is imparted to the fluid (which may, for example, include a mixture of a liquid and solid particles). In the system of U.S. Pat. No. 7,520,997, a rotating shaft which imparts rotation motion to an impeller (to impart rotation motion to the fluid) is hollow and includes an opening via which liquid substantially free of solid particles exits the system. No fluid pressure or downward force is imparted to the fluid by the impeller vanes of U.S. Pat. No. 7,520,997.
Although a number of separation devices, systems and methods have been developed for separating materials based upon differences in densities (for example, separation of solid particles from liquids) it remains desirable to develop improved separation devices, systems and methods.